The present invention broadly relates to an improved apparatus for winding up printed products arriving in imbricated formation.
Generally speaking, the winding apparatus of the present development has a rotatably journaled and drivable winding mandrel, at least one continuous conveyor delivering the printed products to the winding mandrel and which is pivotably journaled and capable of bearing on the winding mandrel, respectively on the product coil or wound package forming thereupon, and a winding strap which is capable of being unwound from a winding strap supply roll, brought into contact with the lower side of the imbricated formation, connected to the winding mandrel, placed under tension and wound up on the winding mandrel conjointly with the printed products.
In other words, the apparatus of the present invention is intended for winding up essentially flat products, such as printed products and the like, arriving in an imbricated formation having a lower side and comprises a rotatably journaled and drivable winding mandrel, at least one pivotably journaled continuous conveyor capable of bearing against the winding mandrel for delivering the products to the winding mandrel, a winding strap supply roll as well as a winding strap having a side facing the winding strap supply roll and which is capable of being unwound from the winding strap supply roll, brought into contact with the lower side of the imbricated formation, connected to the winding mandrel, placed under tension and wound up on the winding mandrel conjointly with the products.
A winding apparatus of this type is known from the commonly assigned U.S. Pat. No. 4,438,618, granted March 27, 1984, in which a continuous conveyor, which is constructed as a belt conveyor pivotably journaled at its inner or tail end, is arranged on the underside of a winding strap and is pressed against a winding mandrel, respectively against a product package forming thereupon, by a contact or pressing mechanism. Not only does the engagement angle of the belt conveyor change with increasing package diameter, but also the transfer point or delivery position at which the imbricated product formation together with the winding strap leaves the belt conveyor and runs onto the product package. This migration of the transfer point cannot be maintained under exact control, which means that the winding up procedure proceeds under conditions which cannot be readily predetermined.
This variation of the position of the product transfer or delivery point of the imbricated product formation can be kept within limits if a belt conveyor with a long conveying path is selected, i.e., when the distance between the pivot point of the belt conveyor and the winding mandrel is selected to be relatively great. Such a solution has, however, the disadvantage of a correspondingly great construction length. Furthermore, there is the danger of the printed products sliding upon the belt conveyor if the latter exhibits an excessively steep gradient.